单项选择题
The wheel was probably invented by （）
A．a group of early hunters B．the first men on earth C．a great prehistoric thinker D．the man who made the first cart
单项选择题 The wheel is called （）
单项选择题 What is the author's attitude towards the U. S. Bureau of Labor Statistics（）
单项选择题 What jobs have typically been held by women（）
